The prior art abounds with toolholders for chucking or clamping tools for machines such as lathes, bar machines, milling machines and the like. The most common of such toolholders presently used with bar machines is illustrated in FIG. 1 of the drawing. This most common toolholder as well as all other known toolholders designed for use with bar machines have the disadvantage or drawback in that it is most difficult to adjust the toolholder once it is in a supposed, desired, position on the toolslide of the machine. For example, with the most common prior art toolholder shown in FIG. 1, its adjustment is accomplished by loosening the four bolts which clamp the toolholder to the toolslide and tapping the toolholder with a wrench or the operator's hand. This procedure involves substantial trial and error, numerous taps on each side of the toolholder, is time consuming, and hinders precision adjustments.
U.S. Pat. No. 4,583,434 discloses a precision adjustable toolholder which is secured to the cross slide of a machine by a pair of through-bolts, one of which secures only a fixed base block to the cross slide and the other which secures not only the fixed base block to the cross slide but also an adjustable tool holding block to the cross slide. This construction permits a precision adjustment of the adjustable tool holding block by a vernier screw after the loosening of the through-bolt which passes through both the fixed base block and the tool holding block, but incorporates no way for supporting and retaining the tool holding block, and is intended for use with light-duty machines and not heavy-duty machines such as bar machines which normally require at least four bolts for mounting to the toolslide. The structure disclosed by this U.S. Pat. No. 4,583,434 has the drawback or disadvantage in that it incorporates no way for supporting and holding the tool holding block on the mount member and is not adaptable for use with heavy-duty machines such as bar machines.
In accordance with the present invention, a novel and improved form of precision adjusting toolholder is provided which is reliable in operation, relatively simple in construction, saves time in set-up, permits a quick change of tools, and merely requires the loosening of a minimum number of bolts and the turning of a vernier screw to make a precision adjustment to the tool holding body, and overcomes the drawbacks and disadvantages of known toolholder assemblies, particularly those intended for use with large, complicated, bar or screw machines.
An object of the present invention is to provide a toolholder which requires only a simple operation or movement to cause a precision adjustment to the toolholder.
Another object of the present invention is to provide a toolholder requiring only a simple operation to cause a precision adjustment to the toolholder and which is also simple in construction, yet is durable and relatively inexpensive to manufacture and use.
These objects as well as other objects of the invention will become more readily apparent after reading the following description in conjunction with the accompanying drawings.